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ICD-10-PCS 2027 procedure code

4A0002ZMeasurement of Central Nervous Conductivity, Open Approach

✓ Valid for 2027

Code unchanged since ICD-10-PCS took effect on October 1, 2015. Source: official FY2027 ICD-10-PCS release from CMS. Page updated September 29, 2026. About our data

About 4A0002Z

4A0002Z is the ICD-10-PCS code for a measurement procedure on the central nervous using an open approach with conductivity. In ICD-10-PCS, measurement means determining the level of a physiological or physical function at a point in time.

In plain terms, this corresponds to other nonoperative neurologic function tests, the ICD-9-CM procedure title it maps to (89.15).

The same procedure with a different approach is coded 4A00X2Z (external).

With a different device, use 4A0004Z (electrical activity) and 4A000BZ (pressure).

It doesn't appear in the MS-DRG procedure index, so on its own it doesn't change the DRG assignment.

It has been valid since ICD-10-PCS took effect on October 1, 2015.

What each character means

1. Section
4Measurement and Monitoring
2. Body System
APhysiological Systems
3. Operation
0Measurement

Determining the level of a physiological or physical function at a point in time

4. Body System
0Central Nervous
5. Approach
0Open

Cutting through the skin or mucous membrane and any other body layers necessary to expose the site of the procedure

6. Function / Device
2Conductivity
7. Qualifier
ZNo Qualifier

Other versions of this procedure

Different approach

ICD-9-CM equivalent

Converter →
  • 89.15Other nonoperative neurologic function testsapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about 4A0002Z

Is 4A0002Z a valid ICD-10-PCS code for 2027?

Yes. 4A0002Z is valid for inpatient procedures from October 1, 2026 through September 30, 2027.

What is the ICD-9 procedure code for 4A0002Z?

The CMS GEMs map 4A0002Z to ICD-9-CM 89.15 (Other nonoperative neurologic function tests).